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D. CROTHERS, M. D., (EDITOR.) HARTFORD, CONN. CONTENTS. CONTRIBUTED ARTICLES. The Neurofibrillar Structures in the Ganglia of the Leech On the Increase in the Number of Medullated Nerve Fibers in the Ventral Roots of the Spinal Nerves of the Growing White Rat. By SHINKISHI HATAI. (From the Neurological Laboratory of the University of Chicago) On the Medullated Nerve Fibers Crossing the Site of Lesions in the Brain of the White Rat. By S. WALTER RANSON, Instructor in Anatomy, Marion-Sims-Beaumont Medical School, St. Louis University. (From the Neurological Laboratory of the University of Chicago.) With Plate VII On the Density of the Cutaneous Innervation in Man. By CHARLES E. INGBERT. (From the Neurological Laboratory of the University of Chicago.) On a Law Determining the Number of Medullated Nerve PAGE 157 177 185 209 223 THE JOURNAL OF Comparative Neurology EDITED BY C. L. HERRICK, SOCORRO, NEW MEXICO. ASSOCIATED WITH OLIVER S. STRONG, COLUMBIA UNIVERSITY, AND WITH THE COLLABORATION OF LEWELLYS F. BARKER, M.B., University of Chicago and Rush Medical College; FRANK J. COLE, University of Liverpool; HENRY H. DONALDSON, Ph. D., University of Chicago; PROFESSOR LUDWIG EDINGER, Frankfurt. a-M.; PROFESSOR A. Van GEHUCHTEN, Université de Louvain; C. F. HODGE, Ph.D., Clark University; G. Carl Huber, M.D., University of Michigan; B. F. KINGSBUry, Ph.D., Cornell University and the New York State Veterinary College; FREDERIC S. LEE, Ph.D., Columbia University; ADOLF MEYER, M.D., Pathological Institute, New York; A. D. MORRILL, M.S., Hamilton College; G. H. PARKER, S.D., Harvard University. Published by the Editors, Denison University, Granville, Ohio. JOURNAL OF COMPARATIVE NEUROLOGY AND PSYCHOLOGY. The enlargement of scope and editorial facilities of The Journal of Comparative Neurology announced on the Editorial page of this issue has led to a change in the name of the publication, as indicated in the caption of this notice, the change to take effect with the first issue for 1904. The Board of Editors remains as before, save that DR. ROBERT M. YERKES, of the Harvard Psychological Laboratory, becomes the responsible editor for the Department of Animal Pehavior and the staff of Collaborating Editors is considerably enlarged. Collaborators PROFESSOR J. MARK BALDWIN, Johns Hopkins University. DR. A. BETHE, Strassburg. PROFESSOR G. E. COGHILL, Pacific University, Oregon. DR. F. J. COLE, University of Liverpool. PROFESSOR H. E. CRAMPTON, Columbia University. PROFESSOR CHARLES B. DAVENPORT, The University of Chicago. PROFESSOR HENRY H. DONALDSON, The University of Chicago. DR. S. I. FRANZ, Dartmouth College. PROFESSOR A. VAN GEHUCHTEN, University of Louvain. PROFESSOR ROSS GRANVILLE HARRISON, Johns Hopkins University. DR. S. I. HOLMES, The University of Michigan. DR. ED. B. HOLT, Harvard University. PROFESSOR G. CARL HUBER, The University of Michigan. PROFESSOR HERBERT S. JENNINGS, The University of Pennsylvania. PROFESSOR B. F. KINGSBURY, Cornell University. PROFESSOR FREDERIC S. LEE, Columbia University. PROFESSOR JACQUES LOEB, The University of California. DR. ADOLF MEYER, Pathological Institute of the New York State Hospitals. PROFESSOR WESLEY MILLS, McGill University. PRINCIPAL C. LLOYD MORGAN, University College, Bristol. PROFESSOR T. H. MORGAN, Bryn Mawr College. PROFESSOR A. D. MORKILL, Hamilton College. PROFESSOR HUGO MÜNSTERBERG, Harvard University. PROFESSOR W. A. NAGEL, Berlin. PROFESSOR G. H. PARKER, Harvard University. PROFESSOR WM. MORTON WHEELER, American Museum of Natural History. Subscription Price $4.00 a Year. (Foreign Subscription $4.30) post-paid. Address all business correspondence to the Manager, C. JUDSON HERRICK, Denison University, Granville, Ohio. THE JOURNAL OF COMPARATIVE NEUROLOGY. THE RATE OF THE NERVOUS IMPULSE IN THE VENTRAL NERVE-CORD OF CERTAIN WORMS. BY O. P. JENKINS AND A. J. CARLSON. (From the Hopkins' Seaside Laboratory and the Physiological Laboratory of Leland Stanford, Jr. University.) With 14 Figures. The physiological properties of the muscles in different species of worms have been investigated by BIEDERMAN (1, 1889), FÜRST (2, 1889), UEXKÜLL (3, 1896), BOTTAZZI (4, 1898), STRAUB (5, 1900), and BUDDINGTON (6, 1902), and the physiological effects of sectioning the ventral nerve cord, extirpation of portions of the same, and extirpation of the œsophageal ganglia have been studied by LOEB (7, 1894), FRIEDLÄNDER (8, 1894), and MAXWELL (9, 1897); but no observations on the rate of propagation of the nervous impulse appear to have been made in this phylum. In this paper we record some measurements, done by the graphic method, of the rate of nervous impulse in the following species: 1 The two nemertians worked on were identified for us by Professor R. W. COE of Yale University as belonging to this genus, species probably new. The marine annelids were identified for us by Professor H. P. JOHNSON of Harvard University. Some of them are new species described by Professor |